General Description
The MXB7846 is an industry-standard 4-wire touchscreen controller. It contains a 12-bit sampling analogto-digital converter (ADC) with a synchronous serial interface and low on-resistance switches for driving resistive touch screens. The MXB7846 uses an internal +2.5V reference or an external reference. The MXB7846 can make absolute or ratiometric measurements. In addition, this device has an on-chip temperature sensor, a battery-monitoring channel, and has the ability to perform touch-pressure measurements without external components. The MXB7846 has one auxiliary ADC input. All analog inputs are fully ESD protected, eliminating the need for external TransZorb™ devices.

Features
♦ ESD-Protected ADC Inputs
    ±15kV IEC 61000-4-2 Air-Gap Discharge
    ±8kV IEC 61000-4-2 Contact Discharge
♦ Pin Compatible with MXB7843
♦ +2.375V to +5.25V Single Supply
♦ Internal +2.5V Reference
♦ Direct Battery Measurement (0 to 6V)
♦ On-Chip Temperature Measurement
♦ Touch-Pressure Measurement
♦ 4-Wire Touch-Screen Interface
♦ Ratiometric Conversion
♦ SPI™/QSPI™, 3-Wire Serial Interface
♦ Programmable 8-/12-Bit Resolution
♦ Auxiliary Analog Input
♦ Automatic Shutdown Between Conversions
♦ Low Power (External Reference)
    270µA at 125ksps
    115µA at 50ksps
    25µA at 10ksps
    5µA at 1ksps
    2µA Shutdown Current

Applications
    Personal Digital Assistants
    Portable Instruments
    Point-of-Sales Terminals
    Pagers
    Touch-Screen Monitors
    Cellular Phones